1. Field of the Invention
The present invention relates to an electroluminescent device and a process for preparing the same.
2. Description of Related Art
An electroluminescent device which is practically employed is composed of a ZnS matrix and a manganese atom contained as an electroluminescent center element in the matrix. In order to produce a thin film electroluminescent panel which has high luminance and reliability and which is capable of driving at a low voltage, high crystallinity of the electroluminescent device is significant.
The electroluminescent device is conventionally produced by an electron beam vapor deposition method which employs pellets of a mixture of ZnS and Mn, or by an atomic layer epitaxy method wherein Zn, Mn and S vapors are alternatively provided onto a substrate to each accumulate one atomic layer. The electron beam vapor deposition method is very simple and suitable for mass production, but the obtained device is poor in reliability and luminance and can be driven at as high as 200 volts. The atomic layer epitaxy method imparts high crystallinity for which the obtained device is excellent in reliability and luminance, but it is difficult to mass produce because of a low film-forming rate.